Recently, in order to respond to a demand for weight reduction in automobile parts and aircraft parts, light metals such Al alloys are often used. However, when a light metal is used, generally, it is necessary to combine the light metal with a secondary material which can provide the required characteristics, so as to compensate for problems in characteristics in the light metal, such as strength at elevated temperature, wear resistance and coefficient of thermal expansion (see Japanese Laid-open Utility Model No. 5-71474, specification (Page 1)).
In the combining, while there was an advantage in obtaining the characteristics, there was a disadvantage of having a low joining strength due to combining different kinds of materials, and there was therefore a problem in that the materials are easily peeled when external force acted on the materials or the materials were exposed to environments having large temperature variations. As efforts to solve the problem, a technique in which an oxide film on the surface of the secondary material which prevents good joining is removed by micronized catalyst in casting is performed. Alternatively, in producing cylinder heads for engines, oxide films on the surface of the secondary material are removed under vacuum, the surface is protected by plating with Ti-based thin film, and the secondary material is integrally cast with Al metal (see Japanese Laid-Open Patent No. 6-218519, specification (Page 1)).
In methods other than the chemical methods, in producing the cylinder bore portion of the cylinder block, cylinder liner is press fitted after casting Al alloy, whereby the combining is performed in a mechanically adhesive condition.
In the above-mentioned conventional composite material member, strength and durability in a joined part between constituent materials of the composite material member are firmly improved. However, all techniques have problems in that the production process is complicated or the material is expensive, whereby the cost is high. That is, micronized metals used as catalysts are precious metals such as Au, Ag and Pt. In a process in which Ti-based thin film is provided, cost is high due to performing in vapor phase by a PVD method. The combining by mechanical press fitting involves a finish processing at high accuracy of an internal diameter and an external diameter, and a press fitting process. Therefore, there was a problem in that production cost of the composite material member produced by these methods were high.